Catalogue oj Non-Calcareous Sponges. 45 



of the short connecting fibres. The spined echinating styli are 

 but sparingly developed. The smooth styli are very irregular 

 in their distribution ; they may be abundant towards the dermal 

 surface, projecting oljliquely from the horny fibre in a plumose 

 fashion. There is usually no special dermal skeleton, but in one 

 specimen there are loose dermal tufts of the slender oxea which 

 give the surface a hispid character. 



Megascleres, (a) long, smooth, straight, slender oxea ; rather 

 abruptly pointed ; size about 0-27 by 0-0042 mm. ; (b) very 

 slightly curved, smooth, gradually and usually linely-pointed 

 styli or subtylostyli ; size about 0-19 by 0-0072 mm. ; (c) spined 

 styli ; short, straight, gradually sharp-pointed, sparingly spined ; 

 size about O'l by 0'006 mm. 



R.^'. 269 (20 f ; "dull brownish red ") ; 633 (x, 19 f ; " ochra- 

 ceous-rufous ") ; 928 (x A) ; 1033 (x B). 



Echinodictyum spongiosum, n. sp. 



Encrusting, irregular ; may be massive, proliferous, lobulated. 

 Vents minute or of fair size, scattered. Texture soft and 

 spongy. Colour in spirit pale greyish-yellow. 



Skeleton a very loose network of multispicular, whispy fibi'es, 

 mostly bi'anching otF from one another at acute angles and 

 running towai'ds the surface. The tylote S23icules, of which the 

 fibre is chiefly composed, are invested and held together by a 

 considerable amount of very j)ale-coloured spongin, and are here 

 and there echinated by spined styli. The fibres divide up into 

 almost single spicules as they approach the surface, but there is 

 no properly developed dermal skeletoh. The whole skeleton is 

 very lax, and a good many loose spicules are scattered between 

 the fibres. 



Megascleres, (a) straight or nearly straight, slender tylota ; 

 with cylindrical shaft and small ovoid head at each end ; size 

 about 0-19 by 0"0028 mm.; (b) spined styli or substylostyli ; 

 straight, sharply pointed, with small sharp spines irregularly 

 distributed but most abundant at the base; size about 0'087 by 

 0*0042 mm. As compared with the tylota these spicules are very 

 scarce, and their presence might easily be overlooked. 



B.X. 790 (Sorrento Jetty; "sponge grey"); 946 (s. 9). 



